Industrial-rated circuit breakers generally include a primary and secondary latching arrangement for providing adequate latching of the circuit breaker operating mechanism while maintaining a low level tripping force to release the operating mechanism under overcurrent circuit conditions of predetermined duration.
U.S. Pat. No. 4,550,300 entitled "Latch Release Mechanism for Molded Case Electric Circuit Breakers" describes the arrangement of one such primary and secondary latch assembly.
When a so-called "latch pin" is used in contact with the latch plate, the end of the latch pin in contact with the latch plate must be carefully machined and polished and arranged in a manner to ensure adequate latching of the operating mechanism cradle to prevent the cradle from rotation against the bias force exerted by the powerful operating mechanism springs while allowing a relatively moderate tripping force to move the latch pin away from the latching plate to thereby release the cradle.
U.S. Pat. No. 3,810,051 entitled "Circuit Breaker Trip and Latch Mechanism" describes the use of a roller or rotating pin in contact with the latch lever to minimize the friction between the latch pin and the latch lever.
U.S. Pat. No. 4,911,624 entitled "Reduced Friction Vane Design for Rotary Compressors" describes the use of a roller within a rotary compressor to provide rolling contact with a rolling piston within the compressor. An oil reservoir maintains a constant supply of oil to the roller to reduce friction and wear.
One purpose of the instant invention is to provide a secondary latch pin which maintains sufficient latching force to restrain the circuit breaker operating mechanism during quiescent circuit conditions while allowing a reduced tripping force to release the circuit breaker operating mechanism under overload circuit conditions.